Left Heart Volume and Mass Quantification in Children with Left Ventricular Pressure Overload

Abstract

This investigation was designed to quantify left ventricular and left atrial volume, volume change, systolic output, and ventricular mass in 31 patients with isolated left ventricular pressure overload secondary to aortic stenosis (AS, n = 14) or coarctation of the aorta (n = 17). These parameters were compared with normal standards and with data from a group of nine patients with a combined pressure and volume overload due to aortic stenosis plus aortic or mitral insufficiency (AS + AI or MI). Volumes were calculated from biplane cineangiocardiograms exposed at 60 frames/sec. Left ventricular end-diastolic volume (LVEDV) was significantly lower than normal in patients with AS (57 ± 11 cc/m 2 ), but was normal (73 ± 12 cc/m 2 ) in patients with coarctation. An increase in the ejection fraction (LVEF) was found in both groups averaging 0.73 ± 0.12 in AS patients and 0.69 ± 0.09 in coarctation patients. Patients with AS + aortic or mitral insufficiency (AI or MI) showed elevated LVEDV (103 ± 29 cc/m 2 ), but had a normal ejection fraction. The LV mass was significantly increased in all groups: normal, 82 ± 10 g/m 2 ; AS, 126 ± 41 g/m 2 ; coarctation, 130 ± 44 g/m 2 ; and AS + AI or MI, 168 ± 42 g/m 2 . The left ventricular systolic index and left atrial maximal volume were both normal in patients with pure pressure overload but were significantly increased in patients with combined pressure and volume overload. The low LVEDV in patients with AS as well as the normal volume in patients with coarctation occurred in the presence of elevated LV end-diastolic pressure and indicates a decrease in LV diastolic distensibility in patients responding to an isolated LV pressure overload by significant muscular hypertrophy without dilatation.